Electric discharge device



May 31, 1955 E. GERMER ELECTRIC DISCHARGE DEVICE Filed Jan. 20 1951ATTORNEY INVENTOR. Edmund ELECTREC :orscnnnon nnvrca Edmund Germer,Berlin-Wannsee, Germany, assignor to Hanovia Chemical & Mfg. o., Newark,N. J., a corporation of New Jersey Application January 20, 1951, SerialNo. 206,974

3 Claims. (Cl. 313-4212) This invention relates to electric dischargedevices and is concerned in particular with arrangements for electrodesand terminals in such devices.

Electric discharge devices fail during operation usually because offailure of the electrodes or of a lead-in conductor connecting anelectrode to a contact terminal of the device. The electrodes may becomebroken or when activated electrodes are used they may in time becomeinactivated, whereby the device can no longer function in the manner forwhich it was designed.

it is a general object of the invention to provide an electric dischargedevice having a substantially longer useful life than devices of suchtype manufactured heretoforc. Another object is to provide a dischargedevice having the above stated advantage and yet is simple inconstruction and inexpensive to manufacture. A further obiect of theinvention is to construct the new device in a manner whereby it may beemployed in conjunction with already existing auxiliary equipment suchas lamp sockets, reflectors, etc., without requiring alteration of suchauxiliary equipment. advantages will appear from the following detaileddescription, taken in connection with the accompanying drawing in which:v

Fig. 1 is a view, partly in section, of a discharge device constructedaccording to the invention,

Fig. 2 is an end view of the electrode structure of the deviceillustrated in Fig. 1,

Fig. 3 is an end view of thedevice shown in Fig. 1, and

Pig. 4 is a cross-sectional View of a modified terminal pin for a deviceconstructed according to the invention.

Like numerals designate corresponding parts throughout the several viewsof the drawing.

Broadly stated, the invention resides in the provision in a vapordischarge device of a plurality of electrodes and connecting them to thecontact terminals of the der vice in a suitable manner, whereby uponfailure of one electrode, or of a lead-in conductor, another electrodemay be readily connected to the source of current and the device againbe used as before the failure.

Referring now to Fig. l of said drawing, there is illustrated a lamp,constructed in accordance with the invention, having an envelope 5 oflight transmissive material. If the lamp is designed to emitultra-violet rays, its envelope is formed of quartz or otherultra-violet transmissive material as is well understood by thoseskilled in the art. The lamp may be of the known fluorescent type, i. e.it may have a coating of fluorescent material on its inner surface forconverting invisible radiations to visible light. The lamp is preferablyfilled with rare gas and contains a small amount of mercury or othervaporizable metal. Each end of the tubular envelope 5 is closed by aflared seal-stem 6 in known fashion.

Stem 6 has three lead-in conductors 7, 8 and 9 vacuum tightly sealedtherein for supporting the two electrodes 10 and 11 within the envelope.The center conductor 7 is provided with a head 12. on its inner endwhich may be suitably formed by bending the end of the Wire 7 as Furtherobjects and various 23%,75'? Fate-rated May 31, 1955 shown in thedrawnig. Electrode 11) is fastened to the end of wire conductor 8 and tothe head 12 while electrode 11 is connected between head 12 andconductor 9. The head 12 separates the two electrodes so that heat fromone of them will not be directly conducted to the other during operationof the lamp. Electrodes 1d and 11 may be of the known activated ornon-activated types depending on the use for which the lamp is designed.

A plate 13 of electrically non-conductive material and having twoterminal pins 14 and 15 attached, is held on the envelope by means of aflanged sleeve 16. The center conductor 7 is electrically connected tothe pin 14 while the pin 15 is electrically connected to conductor 9.Conductor 8 passes through a hole 17 in the plate 13 and is connected toa metal sleeve 18 around the pin 15, metal sleeve 18 being insulatedfrom pin 15 by a layer 19 of paper or other suitable insulationmaterial. In order that the diameter of the combined layers comprisingpin 15, insulation layer 19 and metal sleeve 18 may not be excessivelygreater than the diameter of terminal pin 14, the pin 15 may be made tohave a diameter that is smaller than that of the pin 14-, whereby thelamp will readily fit into sockets of common construction.

As is best shown in Fig. 2, each of the electrodes 1% and 11, may belocated nearer to the axis of the tubular envelope by bending the innerportion of the center conductor '7' out of the plane of the conductors 8and 9 Whereby the electrodes 11) and 11 lie substantially side by side,rather than in an end to end relation.

When the lamp, illustrated in Fig. 1, is connected into an electriccircuit, current will pass between the terminal pin 14 and the metalsleeve 1% on the terminal pin 15, through the lead-in conductor 7,electrode 11) and leadin conductor 8, whereby the electrode 10 willbecome heated and in a short time will cause an arc to form between itand an electrode located in the opposite end of the lamp, all as is Wellunderstood by those skilled in the art.

When the electrode 143 fails for any reason as by being burned out or bybecoming inactivated, if originally activated, it may be easilydisconnected from the electric circuit by merely cutting the portion ofconductor 8 that extends out through the hole 17 in the end plate 13.Electrode 11 may then be energized by removing the sleeve 18 and thelayer 19 of insulating material to expose the terminal pin 1% to whichthe electrode is connected through the lead-in conductor 9.

Referring now to the modification illustrated in Fig. 4, in place of theterminal pin 15, there may be provided a terminal comprising a centermember Ztl of electrically non-conductive material covered by a ring 21having an electrically conductive portion 22. The leadin conductors 23and 24 corresponding to the conductors it and 9 shown in the embodimentof Fig. I extend along the length of the center member 2t? and are heldin place by being fitted into a groove on each side of the member 20.Electrical contact is made with either of the conductors 23 or 24 byturning the ring 21 so that its electrically conductive portion 22 willbe positioned against one of the conductors, depending on which of theelectrodes is to be energized.

The invention is also adapted for use in devices employing self-heatedelectrodes. Such devices require only one terminal pin in each endthereof connected by a single lead-in conductor to an electrode. In adevice of this type constructed according to the invention, two or moreelectrodes may be positioned Within the envelope, each supported on itsown lead-in conductor, there being, of course, no contact between thevarious electrodes. The' outer ends of the several lead-in conductorsmay then be connected to a single composite terminal in the mannerillustrated in Figs. 1 and 4.

While I have described the invention more specifically with reference toa mercury or other vapor lamp, which may be a low pressure lamp, e. g. agermicidal or fluorescent lamp, or a high pressure lamp, it Will benoted that the invention is equally applicable to other types ofelectric discharge devices having a gaseous or metal vapor filling, orboth.

The foregoing disclosure is to be regarded as descriptive andillustrative only and not as restrictive or limitative of the invention,of which obviously an embodiment may be constructed without departingfrom the general scope herein indicated and denoted in the appendedclaims.

What I claim is:

1. An electric discharge device having an envelope of vitreous materialand containing a rare gas filling, three lead-in conductors vacuumtightly sealed in said envelope and passing through said envelope, twoelectrodes, said electrodes bridging the inner ends of each of saidconductors, the outer end of two of said conductors being connected to afirst projection supported on and outside of said envelope, the outerend of the third conductor being connected to a second projectionsupported on the outside of said envelope, said projections beingadapted for connection into an electric circuit for energizing saiddevice, said first projection including an electrically nonconductivemember maintaining the outer ends of said two conductors out ofelectrical contact with each other and a movable member embracing theouter ends of said two conductors, said movable member comprising anelectrically conductive portion selectively engageable with either ofsaid two conductors.

2. An electric discharge lamp having a tubular envelope of vitreousmaterial and containing a rare gas filling and a small quantity ofvaporizable metal, three leadin conductors vacuum tightly sealed in atleast one end of said envelope whereby said conductors have a portionextending outside of said envelope and a portion extending inside ofsaid envelope, two electrodes Within said envelope, first and secondprojections supported outside of and on said end of said envelope, saidelectrodes bridging the inner ends of said conductors, the outer end oftwo of said conductors being connected to said first projection, theouter end of the third conductor being connected to said secondprojection, said projections being adapted for connection into anelectrical circuit for energizing said lamp, said first projectionincluding an electrically non-conductive member maintaining the outerends of said two conductors out of electrical contact with each otherand a movable member embracing the outer ends of said two conductors,said movable member comprising an electrically conductive portionselectively engageable With either of said two conductors.

3. An electric discharge lamp having a tubular envelope of vitreousmaterial and a filling of rare gas, at least one electrode in one end ofsaid envelope, at least two electrodes in the other end of saidenvelope, the electrode in said one end being spaced from the electrodesin said other end for supporting an arc therebetween, at least threelead-in conductors tightly sealed in said other end, one of: saidconductors being connected to each of said two electrodes, the others ofsaid conductors being each connected to one of said two electrodes,first and secend terminal pins mounted on said other end of saidenvelope, one of said conductors being connected to the second pin, theothers of said conductors being connected to the first pin, said firstpin including insulating means maintaining said other conductors out ofelectrical contact with each other and a movable member embracing theouter ends of said other conductors, said movable member comprising anelectrically conductive portion selectively engageable with one of saidother conductors.

RzE-erences Cited in the file of this patent UNITED STATES PATENTS678,320 Miller July 9, 1901 1,436,807 Jaeger Nov. 28, 1922 1,551,463Brown Aug. 25, 1925 1,841,680 Brindel Jan. 22, 1932 2,099,305 Lampl Nov.16, 1937 2,411,679 Cox Nov. 26, 1946 FOREIGN PATENTS 211,940 GreatBritain Feb. 28, 1924

1. AN ELECTRIC DISCHARGE DEVICE HAVING AN ENVELOPE OF VITREOUS MATERIALAND CONTAINING A RARE GAS FILLING, THREE LEAD-IN CONDUCTORS VACUUMTIGHTLY SEALED IN SAID ENVELOPE AND PASSING THROUGH SAID ENVELOPE, TWOELECTRODES, SAID ELECTRODES BRIDGING THE INNER ENDS OF EACH OF SAIDCONDUCTORS, THE OUTER END OF TWO OF SAID CONDUCTORS BEING CONNECTED TO AFIRST PROJECTION SUPPORTED ON AND OUTSIDE OF SAID ENVELOPE, THE OUTEREND OF THE THIRD CONDUCTOR BEING CONNECTED TO A SECOND PROJECTIONSUPPORTED ON THE OUTSIDE OF SAID ENVELOPE, SAID PROJECTIONS BEINGADAPTED FOR CONNECTION INTO AN ELECTRIC CIRCUIT FOR ENERGIZING SAIDDEVICE, SAID FIRST PROJECTION INCLUDING AN ELECTRICALLY NONCONDUCTIVEMEMBER MAINTAINING THE OUTER ENDS OF SAID TWO CONDUCTORS OUT OFELECTRICAL CONTACT WITH EACH OTHER AND A MOVABLE MEMBER EMBRACING THEOUTER ENDS OF SAID TWO CONDUCTORS, SAID MOVABLE MEMBER COMPRISING ANELECTRICALLY CONDUCTIVE PORTION SELECTIVELY ENGAGEABLE WITH EITHER OFSAID TWO CONDUCTORS.